File content as of revision 0:c2c6f009e2d1:

#include "mbed.h"

DigitalOut ledRed(LED_RED);
DigitalOut ledGreen(LED_GREEN);
DigitalOut ledBlue(LED_BLUE);

int flashPattern = 0;

const unsigned char I2C_ADDR_PCF8591T  = 0x9E;
const unsigned char I2C_ADDR_PCA9672PW = 0x46;

const unsigned char LED_ON  = 0;
const unsigned char LED_OFF = 1;
bool keyPressed;
char response[1];

I2C m_i2c(P0_10, P0_11);

unsigned char i2c_wait(int ms)
{
    for(int n=0; n<ms; n+=50)
    {
        //read PCA9672PW
        if (m_i2c.read(I2C_ADDR_PCA9672PW, response, 1) == 0)
        {
            //check if push-button pressed (bit #7 = 0)
            if ((keyPressed == false) && ((response[0] & 0x80) == 0))
                return 1;
        }
        else
        {
            //error reading from I2C device
            while(1)
            {
                for(int i=0; i<10; i++)
                {
                    ledBlue = LED_ON;
                    wait(0.05);
                    ledBlue = LED_OFF;
                    wait(0.05);
                }
                wait(1.0);
            }
        }
        wait(0.05);
    }
    return 0;
}

int main() {
    //init RGB-LED to be off
    ledRed   = LED_OFF;
    ledGreen = LED_OFF;
    ledBlue  = LED_OFF;

    //test i2C connection with PCF8591T  (1.0.0.1.1.1.1.rw)
    const char command1[] = {0x00};
    if (m_i2c.write(I2C_ADDR_PCF8591T, command1, 1) != 0)
    {
        while(1)
        {
            for(int i=0; i<10; i++)
            {
                ledRed = LED_ON;
                wait(0.05);
                ledRed = LED_OFF;
                wait(0.05);
            }
            wait(1.0);
        }
    }

    //test i2C connection with PCA9672PW (0.1.0.0.0.1.1.rw)
    const char command2[] = {0xff};
    if (m_i2c.write(I2C_ADDR_PCA9672PW, command2, 1) != 0)
    {
        while(1)
        {
            for(int i=0; i<10; i++)
            {
                ledBlue = LED_ON;
                wait(0.05);
                ledBlue = LED_OFF;
                wait(0.05);
            }
            wait(1.0);
        }
    }
    
    //startup flash behaviour
    for(int i=0; i<10; i++)
    {
        ledGreen = LED_ON;
        wait(0.05);
        ledGreen = LED_OFF;
        wait(0.05);
    }
    wait(1.0);

    //enter forever loop, change RGB flash patterns with user push-button
    keyPressed = false;
    i2c_wait(1);
    while(1)
    {
        //read user push-button
#if 1
        i2c_wait(1);
        //check if push-button pressed (bit #7 = 0)
        if ((keyPressed == false) && ((response[0] & 0x80) == 0))
        {
            keyPressed = true;
            flashPattern++;
        }

        //check if push-button released (bit #7 = 1)
        else if ((keyPressed == true) && ((response[0] & 0x80) != 0))
            keyPressed = false;
#else
        if (m_i2c.read(I2C_ADDR_PCA9672PW, response, 1) == 0)
        {
            //check if push-button pressed (bit #7 = 0)
            if ((keyPressed == false) && ((response[0] & 0x80) == 0))
            {
                keyPressed = true;
                flashPattern++;
                ledRed = LED_OFF;
                ledGreen = LED_OFF;
                ledBlue = LED_OFF;
            }

            //check if push-button released (bit #7 = 1)
            else if ((keyPressed == true) && ((response[0] & 0x80) != 0))
                keyPressed = false;
        }
        //error reading from I2C device
        else
        {
            while(1)
            {
                for(int i=0; i<10; i++)
                {
                    ledBlue = LED_ON;
                    wait(0.05);
                    ledBlue = LED_OFF;
                    wait(0.05);
                }
                wait(1.0);
            }
        }
#endif        
        //flash RGB-LED according to pattern
        switch(flashPattern)
        {
        case 0:
            ledRed = LED_ON;
            if (i2c_wait(80) != 0) break;
            ledRed = LED_OFF;
            if (i2c_wait(500) != 0) break;

            ledGreen = LED_ON;
            if (i2c_wait(15) != 0) break;
            ledGreen = LED_OFF;
            if (i2c_wait(550) != 0) break;

            ledBlue = LED_ON;
            if (i2c_wait(80) != 0) break;
            ledBlue = LED_OFF;
            if (i2c_wait(500) != 0) break;
            break;
        case 1:
            for(float a=0; a<0.01; a+=0.0004)
            {
                ledGreen = LED_ON;
                wait(a/2);
                ledGreen = LED_OFF;
                wait(0.01-a);
            }
            ledGreen = LED_ON;
            if (i2c_wait(1) != 0) break;
            for(float a=0.01; a>0.0; a-=0.0002)
            {
                ledGreen = LED_ON;
                wait(a/2);
                ledGreen = LED_OFF;
                wait(0.01-a);
            }
            if (i2c_wait(400) != 0) break;
            break;
        case 2:
            ledRed = LED_ON;
            if (i2c_wait(150) != 0) break;
            ledRed = LED_OFF;
            if (i2c_wait(150) != 0) break;

            ledGreen = LED_ON;
            if (i2c_wait(100) != 0) break;
            ledGreen = LED_OFF;

            ledBlue = LED_ON;
            if (i2c_wait(150) != 0) break;
            ledBlue = LED_OFF;
            break;
        case 3:
            ledRed = LED_ON;
            ledGreen = LED_ON;
            ledBlue = LED_ON;
            if (i2c_wait(10) != 0) break;

            ledGreen = LED_OFF;
            ledBlue = LED_OFF;
            ledRed = LED_OFF;
            if (i2c_wait(500) != 0) break;
            break;
        case 4:
            for(float a=0; a<0.01; a+=0.0008)
            {
                ledRed = LED_ON;
                wait(a);
                ledRed = LED_OFF;
                wait(0.01-a);
            }
            ledRed = LED_ON;
            if (i2c_wait(1) != 0) break;
            for(float a=0; a<0.01; a+=0.0008)
            {
                ledBlue = LED_ON;
                wait(a);
                ledBlue = LED_OFF;
                wait(0.01-a);
            }
            ledBlue = LED_ON;
            if (i2c_wait(1) != 0) break;
            for(float a=0.01; a>0.0; a-=0.0008)
            {
                ledRed = LED_ON;
                wait(a);
                ledRed = LED_OFF;
                wait(0.01-a);
            }
            if (i2c_wait(1) != 0) break;
            for(float a=0.01; a>0.0; a-=0.0008)
            {
                ledBlue = LED_ON;
                wait(a);
                ledBlue = LED_OFF;
                wait(0.01-a);
            }
            if (i2c_wait(200) != 0) break;
            break;
        default:
            flashPattern = 0;
            break;
        }
    }
}

#if 0
//https://github.com/mbedmicro/mbed/tree/master/libraries/mbed/vendor/NXP/capi/LPC812
   P0_0 = 0,
   P0_1 = 1,
   P0_2 = 2,
   P0_3 = 3,
   P0_4 = 4,
   P0_5 = 5,
   P0_6 = 6,
   P0_7 = 7,
   P0_8 = 8,
   P0_9 = 9,
   P0_10 = 10, //SDA
   P0_11 = 11, //SCL
   P0_12 = 12,
   P0_13 = 13,
   P0_14 = 14,
   P0_15 = 15,
   P0_16 = 16,
   P0_17 = 17,
   
   D0 = P0_0,
   D1 = P0_4,
   D2 = P0_6,
   D3 = P0_8,
   D4 = P0_9,
   
   D7 = P0_7,
   D8 = P0_17,
   D9 = P0_16,
   D10 = P0_13,
   D11 = P0_14,
   D12 = P0_15,
   D13 = P0_12,
   
   A4 = P0_10,
   A5 = P0_11,
   
   // LPC800-MAX board
   LED_RED = P0_7,
   LED_GREEN = P0_17,
   LED_BLUE = P0_16,
   
   // mbed original LED naming
   LED1 = LED_BLUE,
   LED2 = LED_GREEN,
   LED3 = LED_RED,
   LED4 = LED_RED,
   
   // Serial to USB pins
   USBTX = P0_6,
   USBRX = P0_1,
#endif